pierce



Weighing Sales.

Patented April '9,l 1850.

UNITED STATES PATENT OFFICE.

WM. P. PIERCE, 0F ST. JOHNSBURY, VERMONT, ASSIGNOR TO E. & T. FAIRBANKS& CO.

SCALE-BEAM.

Specification of Letters Patent No. 7,270, dated April 9, 1850.

the following specification and accompanying drawings, letters, figures,and references thereof.

Of the said drawings, Figure l, denotes a .top view of a scale balanceor beam having my improvement applied to each of its suspension loops.Fig. 2, is a front elevation of it. Fig. 3, is a front elevation of itwithout the loops. Fig. 4L, is a vertical and transverse section of it,taken through one of the knife edge bearings, 'and the loop hangingthereon.

In the said drawings A, represents the scale beam. B, C, D, thesuspension loops thereof. E, F, G, the knife edge bearings of the loops.

A considerable inaccuracy in the operation of weighing is often found toresult from the manner in which the hanging loops of the scale beam areusually constructed and applied to it, and this in consequence of thebearing or rubbing of one of the inner faces or surfaces of the loop,against the side of the beam. I/Vhenever this takes place, besides thefriction generated, more or less dirt, or foreign matter is liable tocollect about or on the rubbed surface in such manner as often toconstitute a considerable impediment to the correct operation of anicely adjusted balance or beam. As scale or steelyard beams are used incommerce, the hands of the weigher are so constantly applied to theloops, and in close vicinity of the knife edges, that more or less ofthe foreign matter through them will be deposited on the loops and beam,and this getting between the inner sides of the loops, and on the sidesof the beam, naturally ends in producing friction and wear of thesurfaces of the beam and loop which may be brought into contact. It iscustomary to make the distance between the legs of the loop, where itrests on the knife edge bearings, somewhat greater than the thickness ofthe beam between them, but as one of the two inner edges of the eye endsof the loop, most generally is in contact with the side of the beam, thesame being produced either by inattention or carelessness of the personwho may be using the beam, the above mentioned diiiculty cannot alwaysbe avoided.

In order to overcome the same, I insert in the bar, and directly abovethe knife edge bearing E, F, or G, a vertical plate of hardened steela., whichA is made to extend at each end beyond the surface or side ofthe bar or beam A, and so as to constitute two salients or projectionsZJ, 0, whose two sides are wrought down to angular or knife edges, whichare respectively made to stand at an obtuse angle of about ninety fivedegrees to their respective knife edges f, g, of the bearings of theloop. They not only prevent the loop from contact with and rubbingagainst, either face or side of the beam, but should any sugar, dirt, orother material, liable to affect the operation of the loop, get upon theinner side of the loop, or between it and the adjacent surface of thebeam, the salient b, or c, will scrape off the same, when t-he loopswings.

The plate a, is hollowed out on its upper side, and is inserted in thebeam in a recess properly formed to receive it, and to cause the beam toproject into the hollow of the plate, in such manner that when the pieceof metal I-I, in which the knife edge bearings are made is driven intothese places, they serve to hold the plate a, in place. This will bemore particularly understood, by reference to Fig. t, which denotes asection of part of t-he beam, the piece of metal II, and the plate a,the same being taken at right angles to the beam.

I claim- In combination with the beam, and the knife edge bearings, ofthe loop, the two vertical or nearly vertical projections, salients, orknife edges, o, as arranged with respect to the loop and beam,substantially, 1n the manner, and for the purpose, herein beforespecified.

In testimony whereof I have hereto set ilny signature, this 23d day ofJanuary A. D.

WILLIAM P. PIERCE.

Witnesses JOHN PI.y PADDooK, J. P. BANGROFT.

